Unveiling the state of some underexplored deep coralligenous banks in the Gulf of Naples (Mediterranean Sea, Italy).

Deep coralligenous banks are remote and not yet sufficiently explored habitats, harboring several benthic species living in generally stable conditions. These high biodiversity spots, represent also refugia for numerous demersal organisms from adverse environmental conditions and provide several ecosystem functions. Recently, the wide employ of Remotely Operated Vehicles (ROVs) as standard tools for monitoring programs has shed light on the effects of the increasing human activities and global changes on these sensitive habitats. As a consequence, the impacts of different stress conditions on the slow-growing species of coralligenous communities have become more and more evident. In order to evaluate the status of deep coralligenous banks of Mediterranean Sea, a monitoring project was implemented to improve their knowledge, and to investigate on the principal issues characterizing these communities. In particular, ROV-video analysis revealed, among the main stressors, the increase of sediment resuspension and deposition probably due to trawl fishing, causing a decrease of coralligenous cover. The impact of this pressure leads to an overall loss of diversity and abundance, with changes in community structure and dynamics. Monitoring activities on large spatio-temporal scales are therefore very useful and needed to assess change patterns and to suggest appropriate management and conservation tools.